Alginate–calcium carbonate porous microparticle hybrid hydrogels with versatile drug loading capabilities and variable mechanical strengths

Novel alginate/porous CaCO3 microparticle hybrid hydrogels are facilely fabricated by in-situ release of Ca2+ from CaCO3 microparticles induced by hydrolysis of d-glucono-δ-lactone to reduce pH. The mechanical strength of hybrid hydrogels is easily tunable by the alginate/CaCO3 weight ratio. IBU was adsorbed into the porous CaCO3 microparticles. The embedded porous CaCO3 microparticles endow alginate hydrogels versatile drug loading capability and sustained release, especially for less water-soluble substances. This methodology provides a novel way to create new hybrid hydrogels for biomedical applications.